a) Field of the Invention
The present invention relates to a method of forming a wiring structure suitable for the manufacture of LSIs or the like, and a resultant wiring structure. More particularly, the invention relates to a method of forming a wiring structure and a resultant wiring structure, in which an interlayer insulating film is formed by using a hydrogen silsesquioxane resin film.
b) Description of the Related Art
Forming an interlayer insulating film in a multi-layer wiring structure by a hydrogen silsesquioxane resin film is already known (for example, refer to Japanese Patent Laid-open Publication No. 6-181204).
With such an interlayer insulating film forming method, a hydrogen silsesquioxane resin film is coated over the surface of a high quality CVD oxide film on a semiconductor substrate by spin coating or the like, and thereafter the resin film is thermally processed in an inert gas atmosphere such as N.sub.2 to change the resin film into a pre-ceramic silicon oxide film. The pre-ceramic silicon oxide film is again thermally processed in an oxidizing atmosphere such as O.sub.2 to change the pre-ceramic silicon oxide film into a ceramic silicon oxide film. Pre-ceramic silicon oxide is a precursor of ceramic silicon oxide and has less bridging network than in ceramic silicon oxide and is insoluble to organic solvent.
This method can form a silicon oxide film of 1 .mu.m thick or more without any crack. Such a silicon oxide film becomes a useful interlayer insulating film.